This section provides background information related to the present disclosure which is not necessarily prior art.
Articles of footwear configured for pivoting have been previously proposed. These articles typically include a pivot disposed on a ball portion of a foot. In addition, the periphery of a sole surrounding the pivot does not contact the ground in a uniform manner, which can lead to instability of the foot.
There is a need in the art for a design that overcomes these shortcomings.
Conventional footwear typically includes an upper structure and a sole structure that cooperate to support a foot during use. The upper structure securely receives and positions the foot while the sole structure, which is typically secured to a lower portion of the upper structure and generally between the foot and a ground surface, provides traction, support, and cushioning for the user.
Modern articles of footwear also provide a user with enhanced style and athletic performance and may be specifically designed for use during a particular activity or sport. For example, articles of footwear designed specifically for a particular sport such as baseball, football, or soccer, typically include a relatively rigid outsole and a series of cleats extending therefrom. The rigid outsole, while limiting flexibility, prevents undulations in and/or debris disposed on a playing surface from causing injury to a user's foot by preventing such undulations and/or debris from applying a force through the outsole to the user's foot. Such rigid outsoles may even enhance the ability of the user in making sharp cuts during running and may further support the user's foot by restricting rotation of the foot relative to the outsole.
While a relatively rigid outsole provides a benefit to a user during a particular sport such as baseball, football, or soccer, such a rigid outsole is not suitable for every sport. In running, for example, an article of footwear must concurrently provide the user with a relatively flexible outsole to accommodate motion of the user's foot during use, as well as provide adequate support to the user's foot to absorb impact forces associated with foot strike. An article of footwear intended for running, therefore, typically strikes a balance between support and flexibility.
As described above, articles of footwear may be designed to have an outsole suited for the particular application of the article of footwear. While articles of footwear intended for baseball, football, and soccer may include a relatively rigid outsole and articles of footwear intended for running may include a combination of support and flexibility, neither article of footwear is particularly suitable for use in a sport or activity that requires pivoting and/or torsional movement of a user's foot about a longitudinal axis of the foot. For example, while articles of footwear designed for running provide a user with a degree of flexibility, the flexibility provided typically allows the ball of the foot to rotate about an axis extending substantially perpendicular to a longitudinal axis of the user's foot to allow the foot to bend and flex during running and jogging. While such flexibility may provide some degree of flexibility about a longitudinal axis of the user's foot, such rotation is typically prevented or restricted to limit the amount of roll experienced by a user's foot during running to provide the foot with proper support.
Dancing and aerobics are two activities that require flexation and/or torsional movement of a user's foot about a longitudinal axis of the user's foot. During such activities, a user is required to perform many activities and to perform such activities in rapid succession. For example, a dancer is often required to move from a pivot motion on a ball of the dancer's foot to a lateral motion, transferring weight between the user's feet to perform a particular dance move or step. Likewise, during aerobics, a user often rapidly changes direction—often shifting weight between the user's feet in an effort to perform a particular exercise. In either of the foregoing activities, such movement is accomplished by permitting the user's foot to flex about a longitudinal axis of the user's foot.
Conventional articles of footwear do not typically permit a user's foot to flex about a longitudinal axis of the foot, as described above. Providing an article of footwear with a degree of flexibility about a longitudinal axis of the foot enhances the ability of the article of footwear in allowing a user to rapidly move between various motions, which are typical of dance and/or aerobic activities. As such, an article of footwear that provides adequate support to a user's foot while concurrently permitting the user's foot to flex about a longitudinal axis of the user's foot enhances the ability of the user to perform dance and/or aerobic movements.
In addition to providing a user with the ability to perform enhanced dance and/or aerobic movements, users participating in such activities are particularly concerned with the overall aesthetic appearance of the article of footwear. In many cases, it is desirable that the article of footwear match or be an extension of a costume or outfit specifically designed for a particular dance or aerobic routine. To that end, an article of footwear accommodating the above characteristics with respect to flexation and support that concurrently provides the user with the ability to customize the aesthetic appearance of the article of footwear enhances the overall utility of the article of footwear and, thus, the enjoyment of the user when purchasing and using the article of footwear.